Alll Sony Vaio PCG-x505x series laptops played a small soundfile when switching the Laptop on. Head to 4:20 to hear it : https://www.youtube.com/watch?v=hK0d7tsFJng I had one of these as well and afaik it was a small WAV that was inside the BIOS itself...but im not 100% sure anymore. It was using the Phoenix BIOS with "platform.bin" and "ROM.bin", with "phlash2.exe". PhoenixPhlash Utility 4.0, Release 1.28 (1994-1999) You can unpack it using the phoenixtool...but I wasnt able to find something related to "WAV"... You can download the one from a PCG-505G here : https://www.sony.co.uk/support/en/content/cnt-dwnl/PCG-505G/list So, one option ROM was a wav player routine ? Does anyone know ? Are there other, "modern" BIOS versions that "play sounds" when switching the laptop on ?